Opportunistic radio resource management (RRM) schemes have recently received extensive attention in scientific literature and technological fields. One possible area for which opportunistic RRM can be effective is IEEE 802.11-based wireless local area networks (LANs). Existing IEEE 802.11 based systems suffer from inefficient medium access strategies, namely distributed coordination function (DCF), point coordination function (PCF), and their corresponding amendment supporting quality of service (QoS). Furthermore, it is expected that problems will arise due to lack of sufficient frequency opportunities, due at least to the fact that frequency regulations have not efficiently allocated diverse frequency bands. Consequently, cognitive radio, frequency agile, and opportunistic RRM schemes aim to address the aforementioned critical problems in an optimized fashion, resulting in better spectrum utilization and fair radio resource allocation to associated wireless entities.